A diamond's shape is an important factor and often affects how much sparkle it displays. Round shapes possess the most brilliance. Marquise, Pear, Princess, Radiant, and Emerald cuts are very elegant and also possess great fire. Generally, larger fancy shapes cost a bit less than round diamonds. This is because cutters receive a larger yield when cutting a fancy shape that fits unusual shaped pieces of rough. The length to width ratio is important in choosing a fancy-shape. A good concept to keep in mind is that the longer and narrower a diamond, the less probable it is to have the best optical performance. This is why round and square shapes usually have the most brilliant configurations. Some of the popular length-to-width ratios for fancy shapes are emerald cut 1.5:1, marquise 2:1, princess 1:1, and heart 1:1. Usually, for narrower diamonds like oval, marquise, and pear diamonds, a sign of quality is the absence of a large dark bow-tie appearance in the center.
Also, think about the person who will wear this diamond and where it will be worn. The typical engagement ring stone may need to fit different finger sizes (try our finger size chart at www.davidsdiamonds.com). People match differently with different fancy shapes based on physical appearance and personality. After getting these shape and outline issues resolved, it is useful to check the AGA Cut Class charts for fancy shaped diamonds.
Fancy shape diamonds tend to be more susceptible to fashion trends. A particular shape can be popular for a few years and then become totally uninteresting afterwards. So, if you are sensitive to owning an engagement ring that looks dated then you might want to stay with the timeless quality of a round brilliant cut diamond